1. Field of the Invention
The present invention is directed to a steel sheet pile for forming the wall of an excavation, the sheet piling assembly formed of a plurality of the steel sheet piles and the method of construction the assembly.
2. Description of the Prior Art
As shown in FIGS. 1 and 2, there have been widely utilized for the construction of such sheetpiling wall channel steel piles 1 with joint elements 2 at their side edges or H steel piles 3 with joint elements 4 at the side edges of each of opposed flanges 5 of equal width. These piles 1 and 3 are in use to be driven into the ground in side edge to side edge relationship with the joints elements interconnecting the adjacent piles. The H steel piles 3 are found to be advantageous over the channel piles 1 from an economical standpoint since they have inherent rigidity higher than the channel piles with respect to unit weight and can be designed in less weight or thickness for the same rigidity required in constructing the sheetpiling wall. However, such H steel piles 3 are designed to be arranged in a straight line along the wall of an excavation such as a trench and a well and therefore find themselves impossible in some situations to be placed along a curved portion and a corner portion of the wall, because the remaining flanges 5 that do not act as the joint will certainly jam with each other when the piles 3 are required to be placed with little intervening space therebetween, as shown in FIG. 3, to prohibit an angled positioning of the H steel pile in relation to the adjacent piles. That is, the prior H piles 3 can be angularly disposed with each other only with considerable spaces therebetween which could weaken the sheet piling wall assembly to an unusable extent. In addition, the use of the H steel pile 3 will sometimes incur a problem that the web 6 of each H steel pile 3 traverses the ground so as to divide the ground into separate portions, resulting in less binding forces between the individual portions of the ground on both sides of each web 6 and between the pile 3 and the ground.